In recent years, a number of applications draw images with attractive “transparent data”. Although there is a device which can process the “transparent data”, there are many devices such as a reasonable device and the like which cannot process the “transparent data”.
Even the device which cannot process the “transparent data” executes a process for eliminating a “transparent portion” prior to transmitting the data to the device by a printer driver so that a desired output can be performed. To process the transparent data, a drawing image of a background is necessary and drawing images of one whole page are necessary.
In a “transparent data” processing method in the related art, there is such a technique that drawing images of one page are spooled and divided into a “transparent data portion” and a “portion in which the transparent data portion has been hollowed out” and drawing commands are formed (for example, refer to Japanese Patent Application Laid-Open No. 2001-293936).
However, there are the following problems in the related art.
In the related art, since it is necessary to form the drawing command after the drawing images of one page were spooled, timing for starting the transmission of the drawing command is delayed.
There is also a case where a white stripe (gap) occurs between the “transparent data portion” and the “portion in which the transparent data portion has been hollowed out” due to a calculation error in a printer.
An efficiency deteriorates in the case where there are a number of objects which overlap the transparent data.